1. Field of Invention
The invention relates to an apparatus for the treatment of a medical fluid comprising a fluid treatment machine and a cassette insertable therein substantially consisting of a rigid base body of the cassette with fitted chambers and passages and a foil covering them.
2. Description of the Prior Art
Corresponding cassettes are used in medical engineering, in particular to convey dialysis fluid, blood and the like. Cassettes of this type are described e.g. in DE 198 37 667, WO 84/02473, WO 98/22165 or WO 00/33898.
A cassette is, for example, thus known from DE 198 37 667 A1 which consists of a base body of a cassette with fitted chambers and passages and which is closed by a flexible foil to cover the passages and chambers. It is already described there that the cassette is inserted into a special receiving chamber, e.g. in a dialysis machine. This chamber can, for example, be opened via a pivotable door. The cassette can be inserted into the chamber, with the flexible foil lying opposite a corresponding mating piece at the machine so that the cassette can be operated with the aid of actuators and sensors on the machine side.
Although such apparatus with cassettes have generally been described, the conventional extracorporeal blood circuits or blood tubing systems are usually present in a differential construction. This means that a functional division onto different components is present. Such components, for example bubble traps, flow chambers or injection positions, are connected to one another by tubes and are as a rule connected individually to the respective dialysis machine. The design of such blood tubing systems is very complex in manufacture and handling, with the corresponding effort naturally being extremely time consuming with more complex systems such as an online hemodiafiltration.
On the other hand, conventional extracorporeal blood circuits which are installed in this differential construction have the advantage that they can be designed substantially more flexibly for the respective treatment depending on the demand. The previously known apparatus for the use of cassettes namely had the problem associated with it that they are only usable for a very specific application.